This passage, in isolation, is really weird. Jesus tells us to eat His flesh and Drink His blood. But it is not in isolation. Jesus has using this metaphor of bread throughout the whole sermon He is preaching. Those in the crowd have misunderstood and even protested because what they want is another miracle of feeding so they can have lunch. Instead Jesus starts with their desire for bread and points in a spiritual direction. Some in the crowd mock Him, questioning if He is telling them to turn cannibal and eat Him.
Most of the world lives on grain products for the majority of their diet. Wheat, rice, barley and other crops are called the staff of life because most life cannot be sustained without the easy growing and fruitful farming of grains. In the time of Jesus all the folks in the crowd were dependent upon bread for their continuing life. Jesus parallels this dependence with the dependence we should have on Him. He is to be our source of life. That life begins with believing He really is God the Son and He really did die to take away our sins.
So I encourage you to believe these two truths, then base your life on obeying what Jesus has revealed in the Bible. It may seem restrictive, but it is real life.